Implant

ABSTRACT

An implant serving for surrounding e.g. an intestine on hypodermal implantation in an animal or a human body. The implant includes an outer ring, an inner ring arranged in the outer ring about a joint axis, and a number of anchoring links extending between the outer ring and the inner ring. The inner ring, outer ring and two successive connecting links define an opening in which an anchoring means is secured. The free end of the anchoring means is anchored in fascia. The preferred application for the implant is prophylactic and therapeutic treatment of a hernia, especially a hernia originating from an enterostomy.

The invention relates to a hypodermal implant for surrounding forexample an intestine on implantation into an animal or a human body.

Surgical intervention via the wall of the abdominal cavity causesweakened areas in the musculature of the abdominal cavity and therebyincreased risk of hernia formation.

Such weakened areas form hernial orifices. Via these orifices abdominalorgans, such as intestinal tissue and/or mesentery, or parts of theseorgans can be pressed into so-called hernia sacs and be isolated inthese to a greater or smaller extent.

In many cases such a hernia does not cause the patient any inconveniencebut as the hernia sac and its content are joined, the hernia becomesirreducible and can be felt and seen in practically all positions thatthe body might assume. To this should be added that the hernial orificegradually becomes tight, and the blood supply to the hernia is affected.This can result in volvulus and much and severe pain in the stomach.There is furthermore a risk of infection, gangrene, intestinalperforation, shock and even death.

Hernia formations in connection with an established enterostomy aretherefore not wanted. Such a hernia is typically provoked by physicalexertions, such as lifting or coughing, or can even, especiallyimmediately after the surgical intervention, be provoked by more or lessviolent peristaltic movements or mass movements.

During these physical exertions or movements the intestine and parts ofthe surrounding tissue respectively will be pressed in towards thehernia orifices at the risk of formation of a hernia in the area at thenewly established stoma. For example a bulging hernia will be a greatnuisance when a stoma pouch is to be kept adhered across the stoma asthe adherend of a stoma pouch often is not flexible enough to follow thehernia bulge and will therefore loose its adhesive hold on the skin. Tothis should be added that a hernia can provoke defecation obstructingor—blocking constrictions in the intestine.

A first aspect of the present invention is to provide a hypodermal,biocompatible implant of the kind mentioned in the opening paragraphthat has a simple, inexpensive design and easily can be implanted.

A second aspect of the present invention is to provide a hypodermalimplant that cannot be felt by a patient having the implant implanted.

The novel and unique feature according to the invention, whereby this isachieved, is the fact that the implant comprises an outer ring, an innerring arranged in the outer ring about a joint axis, and a number ofconnecting links extending between the outer ring and the inner ring.

The outer and inner rings can preferably be concentrically arrangedabout their joint axis, the connecting links connecting the two rings ata radial distance from each other.

An implant designed in such a way will appear as a mainly flat ring thatwill not take up much space in the area of e.g. the abdominal cavity,into which it is implanted, and will therefore not be felt by thepatient.

Preferably the implant is designed with thin rings having a small wallthickness, for example between 0.5 and 5 mm so that the rings can yieldin a controlled manner according to the peristaltic movements of theintestine in the area in which the inner ring is surrounding thisintestine.

The connecting links, which for example can be comprised of at least onerod or thread, can advantageously be distributed along the ring with amutual angular distance so that they jointly form a number of openingsbetween the inner ring and the outer ring. The surgeon canadvantageously use these openings during implantation for securing theimplant to a tissue structure.

At least one elongated anchoring means extending outwards from theopening or inner ring to a free end can furthermore be mounted in theopenings. The anchoring means serve for anchoring the implant and secureit on the prefixed implantation site.

Both the implant and the anchoring means can expediently be made of abiocompatible material to ensure that the implant will not provokeirritation or inflammation at the risk of rejection. The material chosenfor the anchoring means must furthermore be flexible so that theanchoring means easily can be directed in direction towards theiranchoring site.

If the implant is made of a flexible material, for example a materialhaving memory, the surgeon will easily be able to press the implanttogether with for example a Pean so that the implant can be kept foldedand can be introduced through the abdominal wall through an incisionsmaller than the diameter of the implant. When the grip of the Pean isreleased, the implant will unfold again to be placed to surround forexample an intestine.

The implant can effectively retain and guide the intestine in an area ofthe abdominal cavity where there is a risk of hernia formations toprevent such hernia formations. The flexibility of the implantfurthermore means that the patient cannot feel it in its implantedstate.

Anchoring means in form of e.g. PROLENE meshes are for example knownfrom the inventor's own international patent application WO 01/08597.The length of the anchoring means can be adapted to the actual anatomicconditions, and the free end can in a simple way be secured in theadjacent fascia with for example knot sutures or staples. The meshes canbe made of any biocompatible, flexible material known in the art.Preferred materials are those that conventionally are used in the artfor hernia treatment.

In a preferred embodiment of the implant according to the invention theanchoring means are embedded in or otherwise integrated in at least theouter ring. This embodiment is especially inexpensive and quick tomanufacture as the entire implant including the anchoring means can bemade in one and the same processing step, for example at moulding orcutting from a larger workpiece.

A section of the intestine that e.g. is to be taken through an abdominalincision to construct a stoma is first taken through the inner ring ofthe implant. The implant is positioned at subcutis where it is securedby means of e.g. a number of knot sutures in the openings. Subsequentlythe free ends of the anchoring means are secured to fascia by means ofe.g. staples or knot sutures.

As the anchoring means are either secured in an opening along the outerring, embedded in either the outer ring or an integrated part of boththe inner ring and the outer ring, friction between the surface of theanchoring means and the area of the intestine passing through and incontact with the inner ring can advantageously be avoided. Such afriction can for example be generated by the peristaltic movements ofthe intestine or mass movements, and repeated friction would at worstresult in the injury of the intestine and its content seeping into andinfecting the abdominal cavity.

An anchoring means can alternatively be distanced from the implant andthereby the intestine by means of at least one thread secured in anopening in the implant and connected to the anchoring means at theanchoring end of this means. A thread preferably made of a biocompatiblematerial can possibly be impregnated in a known way with anantimicrobial preparation such as AgNO₃ or an antibiotic to reduce theinfection risk during and after implantation.

The thickness of the ring walls and the diameter of the rings can be thesame or not and will typically depend on the specific application.Correspondingly the anchoring means can be provided with differentlengths.

The invention will be explained in greater details below, describingonly exemplary embodiments with reference to the drawing, in which

FIG. 1 is a perspective view of a first embodiment of an implantaccording to the invention,

FIG. 2 is a perspective view of a second embodiment of an implantaccording to the invention,

FIG. 3 is a perspective view of a third embodiment of an implantaccording to the invention,

FIG. 4 is a perspective view of a fourth embodiment of an implantaccording to the invention, and

FIG. 5 is a perspective view of a fifth embodiment of an implantaccording to the invention,

Below the invention is described on the assumption that the implant isused for a person who has gone through a stoma operation and that theanchoring means are biocompatible meshes.

FIG. 1 is a perspective view of a hypodermal implant 1 according to theinvention.

The implant 1 has an outer ring 2 and an inner ring 3. The outer ring 2is connected to the inner ring 3 by means of, in this case, a totalnumber of six connecting link 4. A connecting link 4 extends mainlyperpendicularly from the radial inside face of the outer ring in anangle of 180° perpendicularly in on the radial outside face of the innerring. The two rings are at a radial distance from each other arrangedconcentrically about their joint axis.

The connecting links 4 are located at equal angular distance from eachother and form a total number of six openings 5 between the outer ring 2and the inner ring 3. In each opening 5 an elongated mesh 6 is securedfor on implantation anchoring the implant 1 in a subjacent fascia (notshown). The mesh 6 is secured around the section 8 of the outer ring 2that forms part of an opening 5 by means of an anchoring end 7 and isextending to a free end 9 that is fixed to fascia by means of e.g.staples (not shown).

FIGS. 2 and 3 are modifications of the implant in FIG. 1 and like partsare similarly referenced.

In the embodiment 10 in FIG. 2 the mesh 6 is secured in the opening 5via threads 11 extending from the anchoring end 7 of the mesh 6 to thesection 8 of the outer ring 2 that forms part of an opening 5 fordistancing the mesh from the inner ring.

FIG. 3 shows a preferred embodiment 12 of an implant according to theinvention.

The connecting links 4 connecting the outer ring 2 and the inner ring 3are in this embodiment so wide that the anchoring part 7 of the mesh 6can be embedded in at least the section 13 of the outer ring 2 in whicha connecting link 4 ends.

The openings 5 are also in this embodiment used for suturing the implantin a hypodermal area, and the meshes 6 are secured to fascia on the waydescribed above.

FIG. 4 shows a fourth embodiment of the present invention, and likeparts are similarly referenced.

As the previous embodiments, the fourth embodiment of an implant 14 aninner ring 3 and an outer ring 2. The embodiment of FIG. 4 differs fromthe others by the fact that both rings 2,3 only have a very small radialand axial extent, the rings preferably being designed as threadsinterconnected along the outer and inner periphery respectively of therings via a number of similarly thread-shaped connecting links 4. Theseconnecting links form a number of openings 5 or meshes between the tworings 2,3 so that the two rings appear as a flat, annular mesh fromwhich a number of anchoring means are extending in form of meshes 6.Furthermore the meshes, of which a total number of six are shown in thiscase, are extending from the inner ring 3 via the outer ring, which ispartly incorporated in the mesh 6 towards its free end 9 that serves forbeing anchored in fascia. Within the scope of the invention implants canbe made with any kind of expedient number of anchoring means.

This embodiment is made of a flexible, and optionally more or lesselastic, biocompatible material, the many openings or meshes between therings and in the meshes respectively serving for advantageouslyreceiving a suture or staple when the implant is in its implanted state.

The implant is in this embodiment made with a mainly continuous meshwith identical or different mesh size. This embodiment provides maximumpossibility of tissue growing inward without simultaneously preventingthe mass movement or peristaltic movement of the intestine.

FIG. 5 shows a fifth embodiment of the present invention, and like partsare similarly referenced.

The fifth embodiment 15 of the implant according to the presentinvention in FIG. 5 is an alternative to the fourth embodiment in FIG.4. The inner ring 3 has a larger axial thickness than the outer ring 2and the connecting links 4 connecting the two rings 2,3 are made ofstrong thread to thereby distribute loads and stresses equally acrossthe entire extent of the rings.

Preferred radial thicknesses of the rings in the embodiments in FIGS. 1,2 and 3 are 5 mm, preferably 4 mm, and especially 3 mm.

The thickness of the rings of the embodiments in FIGS. 4 and 5 can be assmall as 1 mm and even smaller than 0.5 mm. The axial extent of therings is typically between 0.5 and 5 mm.

The inside diameter of the inner ring corresponds to or is slightlylarger than the outside cross section of the section of intestine whichis to be passed through this ring, and the inside diameter of the outerring is larger than the outside diameter of the inner ring.

Within the scope of the invention it will however be clear to a personskilled in the art that thicknesses and diameters of rings andconnecting links depend on the actual need and such that the flexibilityand retaining capability are not compromised.

The meshes have an initial length sufficiently great to reach the fasciato which the mesh is to be anchored, the surgeon being able to shortenthe mesh to an accurate and sufficient length.

Other types of anchoring means are also comprised within the scope ofthe invention, for example one single thread can just as well serve toanchor the implant in fascia.

The implant according to the present invention has its preferredapplication for prophylactic and therapeutic treatment of a herniaoriginating from an enterostomy.

The implant according to the present invention can however be used inother connections.

For example an implant can be used for surrounding oesophagus to relievean oesophagus hernia or preventing such a hernia from developing in apreviously identified critical site.

1. An implant for implantation into an animal or a human body forpreventing herniation, comprising an outer ring, an inner ring that isarranged in the outer ring about a joint axis, and a number ofconnecting links extending between the outer ring and the inner ring,wherein the inner ring has an outside diameter and the outer ring has aninside diameter that is larger than the outside diameter of the innerring, wherein a connecting link comprises or at least one thread.
 2. Theimplant according to claim 1, wherein the connecting links aredistributed at a mutual angular distance along a ring and jointlyforming a number of openings between the inner ring and the outer ring.3. The implant according to claim 1, wherein the inner ring has a largeraxial thickness than the outer ring.
 4. The implant according to claim1, made of a biocompatible material.
 5. The implant according to claim1, wherein the rings each have a radial extent that is smaller than 5mm.
 6. The implant according to claim 5, wherein the radial extent ofthe rings is smaller than 4 mm.
 7. The implant according to claim 5,wherein the radial extent of the rings is smaller than 3 mm.
 8. A methodfor prophylactic or therapeutic treatment of a hernia at a stomy whichcomprises introducing the implant according to claim 1 on hypodermalimplantation in an animal or a human body.
 9. The method of claim 8wherein the implant is applied to the intestine of the animal or human.10. The implant of claim 1, which is flat in the operative position. 11.The implant of claim 1, wherein the inner and outer rings are located inthe same plane.
 12. An implant for implantation into an animal or ahuman body for preventing herniation, comprising an outer ring, an innerring that is arranged in the outer ring about a joint axis, and a numberof connecting links extending between the outer ring and the inner ring,wherein the inner ring has an outside diameter and the outer ring has aninside diameter that is larger than the outside diameter of the innerring, and at least one elongated anchoring means secured in at least oneopening at an anchoring end and extending outwards from the at least oneopening to a free end.
 13. The implant according to claim 12, wherein ananchoring means is embedded in the outer ring or in at least oneanchoring link or in both the outer ring and the at least one anchoringlink.
 14. The implant according to claim 12, wherein a connecting linkcomprises at least one rod or at least one thread.
 15. An implant forimplantation into an animal or a human body for preventing herniation,comprising an outer ring, an inner ring that is arranged in the outerring about a joint axis, and a number of connecting links extendingbetween the outer ring and the inner ring, wherein the inner ring has anoutside diameter and the outer ring has an inside diameter that islarger than the outside diameter of the inner ring, and wherein ananchoring means is secured in an opening via at least one threadextending out from the anchoring end of the anchoring means.
 16. Animplant for implantation into an animal or a human body for preventingherniation, comprising an outer ring, an inner ring that is arranged inthe outer ring about a joint axis, and a number of connecting linksextending between the outer ring and the inner ring, wherein the innerring has an outside diameter and the outer ring has an inside diameterthat is larger than the outside diameter of the inner ring, and at leastone elongated anchoring means partly extending between two adjacentopenings and partly extending outwards from the inner ring via the outerring to a free end, the section of the outer ring extending between thetwo openings being integrated in an anchoring means.
 17. The implantaccording to claim 16, which forms a total flexible mesh.